1. Fields of the Invention
The present invention relates to a transmission shaft assembly, and more particularly, to a light weight transmission shaft assembly for bearing high torque.
2. Descriptions of the Prior Art
The conventional transmission shaft assembly generally includes a tube and two connectors on two ends of the tube, wherein the tube and the connectors are made by metal which is heavy. The connectors are welded to the two ends of the tube so as to bear high torque. However, the higher torque the transmission shaft assembly outputs, the thicker the wall of the tube is required. Therefore, a tube made by carbon fibers is developed to make the tube of the transmission shaft assembly. Nevertheless, the metal-made connectors cannot be welded to the tube made by carbon fibers. Usually, the connectors are adhered to the two ends of the tube, but the connectors are easily separated from the tube due to high torque applied thereto. The adhesive used to connect the connectors to the tube may become fragile and can be broken at low temperature, such that the connectors shaft relative to the tube. A sleeve is used between the connectors and the tube to reinforce the connection. Alternatively, the tube is mounted to the connectors, and a sleeve is mounted to the connection area between the tube and the connector, the sleeve is adhered to the connector and the tube. Unfortunately, the sleeves are damaged when a high torque is applied. Besides, it is costly for the molds to install the sleeve to the specific position.
The present invention intends to provide a transmission shaft assembly to eliminate the shortcomings mentioned above.